Method for producing a clockwork dial provided with projecting symbols



May 17, 1966 voe'r 3,251,124

METHOD FOR PR CING A CLOCKWORK DIAL PROVIDED WITH PROJECTI SYMBOLS FiledJuly 5, l

FIG. 9

United States Patent 3,251,124 METHOD FOR PRODUCING A CLOCKWORK DIALPROVIDED WITH PROJECTING SYMBOLS Andr Vogt, 63 Rue Jacob Brandt, L'aChaux-de-Fonds, Switzerland Filed July 3, 1961, Ser. No. 121,502 Claimspriority, application Switzerland, July 4, 1960, 7,613/ 60 Claims. (Cl.29--177) Various methods for producing clockwork dials provided withprojecting symbols are already known, according to which the dial plateand the symbols are obtained through galvanoplastic means starting froma mold of insulating material, the surfaces of which are made conductivethrough metallizat-ion. The metallized layer may be removed at the endof the operation, or else, it may be retained for giving a color to thedial or to the symbols.

There are obtained thus dial plates of an electrolytic material, thegrade of which is however lower than that of stamped plates.Furthermore, it is not possible to provide signs indicia or symbols madeof solid gold without this leading to the production of dials also madeof gold, or else, Without resorting to an amount of gold which is muchlarger than that actually required for the formation of gold symbolsalone.

My improved method allows executing clockwork dials which do not showsuch drawbacks.

According to my invention, a mold is produced inside which theimpressions corresponding to the symbols or indicia are provided andthrough which a conductive member is inserted across the bottom surfacesof said irnpressions and, this being done, the surface of theimpressions is rendered electrically conductive, the symbols areproduced through an electrodeposition method, the mold is removed andthe symbols are secured to the dial plate.

The accompanying drawing illustrates an embodiment of my invention,showing how this method may be executed.

FIGS. 1 to 9 of said drawing illustrate diagrammatically the mainsuccessive stages of said method.

According to said method, I begin by producing a mold 1 of plasticmaterial (FIG. 1), for example of polyethylene, polystyrol,polyvinyl-chlorine or epoxydrosin, of which the upper section isprovided with impressions for the formation of the symbols which it isdesired to lay on a dial.

Mold 1 carries a conductive member 2 embedded inside it and formingthe'bottom of impressions, said conductive member being constituted, forinstance, by an old dial. The impressions are obtained by means of amember 3 inserted, for instance, inside the mold of an injection moldingapparatus, not shown, into which the plastic material forming the moldis to be injected. It being understood the mold is made with the member2 in position in the die of the injection molding apparatus.

The surface of the mold (FIG. 2) is first coated with a thin layer ofconductive material 4, say a copper layer, obtained through vacuumdeposition and which has for its result an electric interconnectionbetween the impressions and the conductive member 2. Of course, metalssuch as gold or silver can be used.

By means of a slight operation on a milling machine, for instance, thislayer is removed from the upper surface of the mold so as to allow onlythat section of the layer which lines the impressions to remain inposition. The mold is then dipped into an electrolytic bath, so as toform the symbols 5 by a filling, by electro-deposition, of theimpressions, for instance by means of gold (FIG. 3). The latter isdeposited only inside the recesses, since only these are thenconductive.

ICC

This being done, the upper surface of the symbols is finished oil by asurfacing by means of a diamond or by polishing (FIG. 4), after whichthe finished symbols are protected by means of a copper layer 6, forinstance, which is obtained electrolytically (FIG. 5).

Said protecting layer has a thickness such,-say A of a mm., whichensures a proper protection of said symbols.

Known means, for instance a welding through a resistance, or a weldingby means of supersonic waves, soldering, gluing or the like, are thenresorted to for securing over the protecting layer 6 a support 7 whichmay be constituted, for instance, by a metal ring or plate.

The mold 1 is finally removed by melting or by chem- '(b) Polystyr0l-issoluble in the above-mentioned solvents, and is also soluble in benzene.Moreover, it

melts at temperatures above to C.

(c) P0lyethyleneis, for example, soluble in hydrocarbons at temperaturesabove 65 C. It melts at temperatures above 90 to C.

Further means also known per se and preferably a resistance welding or asupersonic welding, allow securing finally the symbols 5 onto a dialplate 8. The support or carrier 7 is then removed together with theprojecting layer carried by it, so as to provide for the appearance toview of the finished symbols which the difierent securing operationscannot damage by reason of the protecting layer 6 coating their partssubjected to such operations. The removal of the support 7 may beobtained through a series of well-known means, say' through electrolysisor through dissolution by an acid.

The upper surface of the dial plate, may, of course, be entirelyfinished, that is, it may have been previously subjected to the usualfinishing operations and, in particular, to the conventionalelectrolytic treatment.

My improved method is particularly economical since it allows obtainingdials carrying projecting symbols which are made, for instance, of gold,while resorting only to the amount of gold which is strictly requiredfor their execution. This is ascribable chiefly to the presence of thelead 2 embedded in the mold and subsequently removed. The dial plate maybe obtained through any conventional means, for instance, throughstamping. Lastly, the symbols, as also the dial plate, can be finishedindependently of one another and the operations on the dial plate cannotdamage the symbols and vice versa.

Of course, my invention is by no means limited to the method describedhereinabove which may be subjected to many modifications within thescope of the accompanying claims.

Similarly, the symbols may also be obtained separately for instance,through an electrolytic deposit of metal in a mold as before describedwhere the dial to be used for fixing indicia thereon functions as theconductive member 2.

What I claim is:

1. A method for manufacturing a clockwork dial having indicia thereon inrelief comprising, providinga dial having a major face to which indiciaare to be secured and a form, forming the indicia simultaneously inspaced relative positions in said form corresponding to spaced asrelative positions in which said indicia are to be fixed relative toeach other on said major face of said dial with an area of each suchindicia exposed, attaching a rigid carrier to said area of each suchindicia to maintain said indicia in said relative positions upon removalof said form, removing said form from said indicia, positioning saidcarrier and indicia attached thereto in position with said indiciabetween the dial and carrier with said indicia in contact with saidmajor face of said dial to which said indicia are to be secured,permanently securing the indicia on said dial in said relativepositions, and removing said carrier.

2. A method for manufacturing a clockwork dial having indicia thereon inrelief comprising, providing a dial having a major face to which indiciaare to be secured and a form having spaced form cavities thereon,coating only the inner surface of said cavities with a conductivecoating and providing an internal current flow path to said innersurfaces, depositing metal only in said cavities by electrodepositionfor forming the indicia in spaced relative positions in which saidindicia are to be fixed relative to each other on said major face ofsaid dial with an area of each such indicia exposed, attaching a rigidcarrier to said area of each such indicia to maintain said indicia insaid relative positions upon removal of said form, removing said formfrom said indicia, positioning said carrier and indicia attachedthereto. in position with said indicia between the dial and carrier withsaid indicia in contact with said major face of said dial to which saidindicia are to be secured, permanently securing the indicia on said dialin said relative positions, and removing said carrier.

3. A method for manufacturing a clockwork dial having indicia thereon inrelief comprising, providing a dial having a major face to Which indiciaare to be permanently secured, providing a dissolvable form havingcavities therein for forming the indicia, the cavities beingelectrically connected internally of the mold rendering the innersurfaces of said cavities electrically conductive, depositing materialin said cavities only during application of electrical current to saidcavity inner surfaces to form said indicia, said cavities being disposedspaced relative to each other in position corresponding to the spacedrelative positions said indicia are to occupy relative to each otherwhen secured to said dial, attaching a rigid carrier to all of saidindicia subsequent to the deposition thereof to hold said indicia infixed relative positions upon removal of said form, dissolving the formto free the indicia therefrom, positioning the carrier for securing theindicia on said dial, permanently securing said indicia on said dial,and removing the carrier from said indicia so that the indicia remainfixed in position on said dial free of said carrier.

4. A method for manufacturing a clockwork dial having indicia thereon inrelief comprising, providing a dial having a major face to which indiciaare to be permanently secured, providing a dissolvable form havingcavities therein for forming the indicia, the cavities beingelectrically connected internally of the mold rendering the innersurfaces of said cavities electrically conductive, depositing materialin said cavities only during application of electrical current to saidcavity inner surfaces to form said indicia, said cavities being disposedspaced relative to each other in position corresponding to the spacedrelative positions said indicia are to occupy relative to each otherwhen secured to said dial, attaching a rigid conductive carrier to allof said indicia subsequent to the deposition thereof to hold saidindicia in fixed relative positions upon removal of said form,dissolving the form to free the indicia therefrom, positioning thecarrier with indicia thereon in position relative to said major face ofthe dial for securing the indicia on said dial, applying welding currentto said dial and carrier for permanently securing said indicia on saiddial, and removing the carrier from said indicia so that the indiciaremain fixed in position on said dial free of said carrier.

5. A method for manufacturing a clockwork dial having indicia thereon inrelief comprising, providing a dial having a major face to which indiciaare to be permanently secured, providing a dissolvable form havingcavities therein for forming the indicia, the cavities beingelectrically connected internally of the form rendering the innersurfaces of said cavities electrically conductive, depositing materialin said cavities only during application of electrical current to saidcavity inner surfaces to form said indicia, said cavities being disposedspaced relative to each other in position corresponding to the spacedrelative positions said indicia are to occupy relative to each otherwhen secured to said dial, applying a protective coating to an exposedend of said indicia in said cavities, prior to applying said coatingfinishing surfaces on said indicia on which said coating is applied,attaching a rigid carrier to all of said indicia over said coatingsubsequent to the deposition thereof to hold said indicia in fixedrelative positions upon removal of said form, dissolving the form tofree the indicia therefrom, positioning the carrier with indicia thereonin position relative to said major face of the dial for securing theindicia on said dial, permanently securing said indicia on said dial,and removing the carrier from said indicia so that the indicia remainfixed in position on said dial free of said carrier.

References Cited by the Examiner UNITED STATES PATENTS 366,085 7/1887Fitch 29177 1,392,007 9/1921 Freund 29177 1,571,756 2/1926 Colomb 29-1771,648,046 11/1927 Fulton 2049 X 1,995,036 3/1935 Pape 58127 2,011,5178/1935 Geoifrion 58-127 2,608,529 8/ 1952 Varian.

2,761,198 8/1956 Stern 29177 3,076,230 2/1963 Parker et al. 29-423 XJOHN F. CAMPBELL, Primary Examiner.

NEDWIN BERGER, \VHITMORE A. WILTZ, T. D.

SHAFFNER, Examiners.

1. A METHOD FOR MANUFACTURING A CLOCKWORK DIAL HAVING INDICIA THEREON INRELIEF COMPRISING, PROVIDING A DIAL HAVING A MAJOR FACE TO WHICH INDICIAARE TO BE SECURED AND A FORM, FORMING THE INDICIA SIMULTANEOUSLY INSAPCED RELATIVE POSITIONS IN SAID FORM CORRESPONDING TO SPACED RELATIVEPOSITIONS IN WHICH SAID INDICIA ARE TO BE FIXED RELATIVE TO EACH OTHE ONSAID MAJOR FACE OF SAID DIAL WITH AN AREA OF EACH SUCH INDICIA EXPOSED,ATTACHING A RIGID CARRIER TO SAID AREA OF EACH SUCH INDICIA TO MAINTAINSAID INDICIA IN SAID RELATIVE POSITIONS UPON REMOVAL OF SAID FORM,REMOVING SAID FORM FROM SAID INDICIA, POSITIONING SAID CARRIER ANDINDICIA ATTACHED THERETO IN POSITION WITH SAID INDICIA BETWEEN THE DIALAND CARRIER WITH SAID INDICIA IN CONTACT WITH SAID MAJOR FACE OF SAIDDIAL TO WHICH SAID INDICIA ARE TO BE SECURED, PERMANENTLY SECURING THEINDICIA ON SAID DIAL IN SAID RELATIVE POSITIONS, AND REMOVING SAIDCARRIER.